Unit 1: Intro

Unit 1: Intro

1. Reasons for studying concepts of PLs

   • Increased capacity to express programming ideas
   • Increased ability to learn new programming languages
   • Improved background for choosing a programming language
   • Increased ability to design good quality new languages
   • Overall advancement of computing and an improvement in the quality of software

2. Desirable attributes of PLs

   • Expressive
     • Can the machine do it? Yes it can
   • Concise
     • Not much code setup
   • Safe
     • Errors found
   • Easy-to-read
   • Executes efficiently
     • Uses appropriate amount of memory
   • Supporting reuse of code via abstraction
     • No cut and paste required
   • Easy to learn

3. Main Programming Paradigms

   • Imperative PLs
     • Most common PLs portray more active entities (threads)
     • Split into procedural and object-oriented
     • Java, C, Ada, JavaScript...
   • Functional PLs
     • Program and its data are one in the same
       • Compute = transform the program
     • Algebraic calculator concept
     • Haskell, Elm
   • Logical PLs
     • Semi-intelligent agent
       • Can be asked a question and it will deduce an answer based of knowledge from the program

4. Making Programs Execute

   • Interpreted
     • Python, Basic, Lisp, Prolog
     • Interpreter reads and simulates in an abstract machine
   • Compiled and executed directly
     • C, Ada, Haskell
     • Run-time management code (can be an interpreter)
   • Compiled then interpreted
     • Java
     • Virtual environment